I switched from PC to Mac last March, and with a couple of minor exceptions, the transition is complete. I do have one issue that bothers me...

In Windows, an application, such as Photoshop, has a main application window -- a main controlling window that covers the desktop, at least in part, and my documents and pallets float in panels within this window.

On a Mac, the active application does not seem to have the same concept of a main controlling application window, so my document windows and pallets float over my messy desktop.

Two disadvantages to this that I see... one is that an errant mouse click -- one that doesn't' quite touch my document window, gets sent to another application -- whatever window is open behind the one I'm working in, or to a desktop icon if there is one there to be clicked. The other disadvantage is the constant visual distraction of the desktop icons and other open apps.

Not having a Mac, I don't know how to maximize windows on one.
But I do know that this is one of the reasons why people recommend setting your desktop background to a neutral grey in order to prevent color influences seeping in when working with an image processing program such as PS.

Despite a lot of similarities, windows and Mac systems don't behave the same…

if you drag your window frame by the down left corner, it may use all your screen, avoiding to see the 'desktop'
As suggested by Cem if you set a grey bg for your desktop AND if you get no files on desktop, you may find this restfull

In PS CS2 and 3 you may register the position of all your palettes (menu window/workspace) very handy!

If you hit F9 you'll see all opened windows

Closing a window doesn't quit the software (it is still loaded in RAM)

AFAIK there is no trick to have automatically a window being opened full screen…